1. Field of the Invention
The present invention relates to the fields of molecular biology and protein biochemistry. More specifically, the invention relates to fusion proteins that serve as targeted carriers for chemotherapeutic compounds, and methods of use therefor.
2. Related Art
Cancer continues to be one of the leading causes of death world-wide, despite impressive advances in cancer therapy in recent years. One of the most promising avenues of therapy—targeted drug deliver—has proved to be one of the biggest disappointments. Initially, much hope was focused on the use of monoclonal antibodies (mAbs), which are characterized by the high degree of binding selectivity. While preliminary worked demonstrated the feasibility of targeting tumor cell surface receptors, the actual results were less than impressive. Two major limitations inherent in the use of mAbs—their large size and non-specific uptake of antibodies by the liver and reticuloendothelial system—probably contributed significantly to the less than desired results.
Tumor targeting peptides are excellent alternative targeting agents for human cancers, and they may alleviate some of the problems with antibody targeting. In the past decade, various cancer cell surface or cancer-related targeting peptides have been identified by combinatorial methods. Conjugation of these cancer-targeting peptides to either proteins or small molecule anti-cancer drugs showed remarkable improvement in cancer cell selectivity and specificity, demonstrating that these peptides may be the second generation of targeted drug delivery for cancer. Nonetheless, improvements in the application of peptide drug targeting still are desired.